The next Ubuntu version 11.04 Natty Narwhal is coming soon (The final stable version will be released end April 2011), if you intend to upgrade to 11.04 from current Ubuntu version there are few ways you can choose including online and offline upgrading. If you have ubuntu 10.10 Maverick Meerkat or older version of ubuntu installed and you want to upgrade to the latest Ubuntu 11.04 Natty Narwhal, you can do it by following these instructions.
To be safe:
# Make a full backup of your data on an external device (USB stick or CD/DVD).
# Download and burn the liveCD of the newer release, and check that your hardware is fully functional with it.
Desktop Online Upgrade
1# Press Alt+F2
2# type in “update-manager -d”
3# Finally click “Upgrade” and follow the on-screen instructions.
Server Online Upgrade
1# install the update-manager-core package if it is not installed:
$ sudo apt-get install update-manager-core
2# Edit /etc/update-manager/release-upgrades and set Prompt=normal;
$ sudo nano /etc/update-manager/release-upgrades
Then set “Prompt=normal;”
(remember to save it)
3# Launch the upgrade tool:
$ sudo do-release-upgrade -d
(follow the on-screen instructions)
Offline upgrading via Live-CD
Since Ubuntu 11.04 Natty, Ubuntu Live-CD supports upgrading from the previous Ubuntu installation. Download the Ubuntu 11.04 iso and create a Live-CD or Live-USB, then boot from the device, if you have a Ubuntu installed on machine there’s an upgrade option in the installation guide.